DIN Classification of Hydraulic Oils
DIN (Deutsches Institut für Normung eV – German Institute for Standardization) sets out the classification of hydraulic oils in DIN 51524. Accordingly, the oils are classified according to their properties and fields of application.
| Designation | Description |
| HL | Hydraulic fluids mainly with oxidation and corrosion protection additives only, but without specific antiwear additives for mixed friction. HL fluids can be used in hydraulic systems for which there are no wear protection requirements. |
| HLP | Hydraulic fluids with anti-corrosion, anti-oxidation and anti-wear additives. HLP fluids are suitable for most applications and components subject to temperature and viscosity conditions. |
| HVLP | Hydraulic fluids with properties similar to HLP fluids with additional improved temperature performance due to viscosity modifiers. HVLP fluids are used in systems operating over a wide temperature range. |
| HLPD | Hydraulic fluids with HLP characteristics and additional detergent and/or dispersant additives. HLPD fluids are used in systems where the influence of deposits and solid or liquid contaminants must be reduced. |
| HVLPD | Hydraulic fluids with HVLP properties and additional detergent and/or dispersant additives. HVLPD fluids are used in systems where the influence of deposits and solid or liquid contaminants must be reduced. |
Note.
For complete and up-to-date information on the classification of hydraulic oils, please refer to DIN 51524.